Usage Guide For Administrators
==============================

Start API
----------

.. code-block:: sh

    ucloud api

Host Creation
-------------

Currently, we don't have any host (that runs virtual machines). 
So, we need to create it by executing the following command

.. code-block:: sh
    
    ucloud-cli host create --hostname ungleich.ch --cpu 32 --ram '32GB' --os-ssd '32GB'

You should see something like the following

.. code-block:: json

    {
        "message": "Host Created"
    }

Start Scheduler
---------------
Scheduler is responsible for scheduling VMs on appropriate host.

.. code-block:: sh

    ucloud scheduler

Start Host
----------
Host is responsible for handling the following actions

* Start VM.
* Stop VM.
* Create VM.
* Delete VM.
* Migrate VM.
* Manage Network Resources needed by VMs.

It uses a hypervisor such as QEMU to perform these actions.

To start host we created earlier, execute the following command

.. code-block:: sh

    ucloud host ungleich.ch

Create OS Image
---------------

Create ucloud-init ready OS image (Optional)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This step is optional if you just want to test ucloud. However, sooner or later
you want to create OS images with ucloud-init to properly
contexualize VMs.

1. Start a VM with OS image on which you want to install ucloud-init
2. Execute the following command on the started VM

   .. code-block:: sh

    apk add git
    git clone https://code.ungleich.ch/ucloud/ucloud-init.git
    cd ucloud-init
    sh ./install.sh
3. Congratulations. Your image is now ucloud-init ready.


Upload Sample OS Image
~~~~~~~~~~~~~~~~~~~~~~
Execute the following to upload the sample OS image file.

.. code-block:: sh

    mkdir /var/www/admin
    (cd /var/www/admin && wget http://[2a0a:e5c0:2:12:0:f0ff:fea9:c3d9]/alpine-untouched.qcow2)

Run File Scanner and Image Scanner
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Currently, our uploaded file *alpine-untouched.qcow2* is not tracked by ucloud. We can only make
images from tracked files. So, we need to track the file by running File Scanner

.. code-block:: sh

    ucloud filescanner

File Scanner would run, scan your uploaded image and track it. You can check whether your image
is successfully tracked by executing the :code:`ucloud-cli user files`, It will return something like the following

.. _list-user-files:

.. code-block:: json

    {
        "message": [
            {
                "filename": "alpine-untouched.qcow2",
                "uuid": "3f75bd20-45d6-4013-89c4-7fceaedc8dda"
            }
        ]
    }

Our file is now being tracked by ucloud. Lets create an OS image using the uploaded file.

An image belongs to an image store. There are two types of store

* Public Image Store
* Private Image Store (Not Implemented Yet)

.. note::
    **Quick Quiz** Have we created an image store yet?

The answer is **No, we haven't**. Creating a sample image store is very easy.
Just execute the following command

.. code-block:: sh

    (cd ~/ucloud && pipenv run python api/create_image_store.py)

An image store (with name = "images") would be created. Now, we are fully ready for creating our
very own image. Executing the following command to create image using the file uploaded earlier

.. code-block:: sh

    ucloud-cli image create-from-file --name alpine --uuid 3f75bd20-45d6-4013-89c4-7fceaedc8dda --image-store-name images

Please note that your **uuid** would be different. See :ref:`List of user files <list-user-files>`.

Now, ucloud have received our request to create an image from file. We have to run Image Scanner to make the image.

.. code-block:: sh

    ucloud imagescanner

To make sure, that our image is create run :code:`ucloud-cli image list --public`. You would get 
output something like the following

.. code-block:: json
    
    {
        "images": [
            {
                "name": "images:alpine",
                "status": "CREATED"
            }
        ]
    }